From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D88A41AA7A6 for ; Mon, 22 Dec 2025 12:47:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766407637; cv=none; b=Znd/+ttKzPyCvgFSm1Od5vwwVnu/jQmUrXiYyVY4JxkFvtYYqcnPITlBVSfOBsnbOC+MNWPUTXH2U99QX9nhnsAgKfqRY/zTlP9UwjO6w5UKNi0cGNHQSXYgFX3c/eglgEMPh7/GBdgaLe44VTulJmFDT0WaAgwcxLzjr/yAds4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766407637; c=relaxed/simple; bh=9aeHr0UBYKybdnZ7OonhcZ1hc+us6ZVH81XLigqlmVI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=ILEGaIjMRtWMLwkMPHC3EkC9N7g0mp8YBuGjcttbXuEQjQwalxcVPSujKngyhzCPur0z7/PjQntRpbocA3nfSmwmiZkaGhbQIEUImXgIrf0Kb98uq8EmEq5nU9AGwWuJjGmUzed96X9Z7RW4rLBdqWO7S/2DyIHkiR7jvYSyQ2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cy8t3pw0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cy8t3pw0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BDDBC4CEF1; Mon, 22 Dec 2025 12:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766407637; bh=9aeHr0UBYKybdnZ7OonhcZ1hc+us6ZVH81XLigqlmVI=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=cy8t3pw0pI6z1VEeSKS5Eyi2JObgbtA2pdj4c3GSEwuxRBFNTXnnedWnJL9NyFXjM L484bLmd9weWpGMiKXh6KMIoMIXJ4FQu8rWWg/aRycj7R8i4seuWX0UJBrexaCMy4+ o3dZXsQasWE5qYUI2x8hEiHrVtdDrxwOdRtkaMtE4NDAlI0KIsE7H3ZaZXIoApZK3f Q9uirMwguXxOpoLdaKOvWqwWrskzR064gGxZoZHBN+V3XCqkjcdBJUi0gxZT8YwYdU eN1/wnj24j6YL9PSj0H+EtIDiCkG3fbYlVs+YT9M5orLasbir3SVaD8tm1XWV4JMYL XB0JQ5HGckhew== Message-ID: Subject: Re: [PATCH] SUNRPC: xdrgen: Initialize data pointer for zero-length items From: Jeff Layton To: Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: linux-nfs@vger.kernel.org, Chuck Lever Date: Mon, 22 Dec 2025 07:47:15 -0500 In-Reply-To: <20251220154109.1361512-1-cel@kernel.org> References: <20251220154109.1361512-1-cel@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV 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skipped calling xdr_inline_decode() when the > item length was zero. This left the data pointer uninitialized, > which could lead to unpredictable behavior when callers access > it. >=20 > Remove the zero-length check and always call xdr_inline_decode(). > When passed a length of zero, xdr_inline_decode() returns the > current buffer position, which is valid and matches the behavior > of hand-coded XDR decoders throughout the kernel. >=20 > Fixes: 4b132aacb076 ("tools: Add xdrgen") > Signed-off-by: Chuck Lever > --- > include/linux/sunrpc/xdrgen/_builtins.h | 20 ++++++++------------ > 1 file changed, 8 insertions(+), 12 deletions(-) >=20 > diff --git a/include/linux/sunrpc/xdrgen/_builtins.h b/include/linux/sunr= pc/xdrgen/_builtins.h > index 52ed9a9151c4..a723fb1da9c8 100644 > --- a/include/linux/sunrpc/xdrgen/_builtins.h > +++ b/include/linux/sunrpc/xdrgen/_builtins.h > @@ -248,12 +248,10 @@ xdrgen_decode_string(struct xdr_stream *xdr, string= *ptr, u32 maxlen) > return false; > if (unlikely(maxlen && len > maxlen)) > return false; > - if (len !=3D 0) { > - p =3D xdr_inline_decode(xdr, len); > - if (unlikely(!p)) > - return false; > - ptr->data =3D (unsigned char *)p; > - } > + p =3D xdr_inline_decode(xdr, len); > + if (unlikely(!p)) > + return false; > + ptr->data =3D (unsigned char *)p; > ptr->len =3D len; > return true; > } > @@ -279,12 +277,10 @@ xdrgen_decode_opaque(struct xdr_stream *xdr, opaque= *ptr, u32 maxlen) > return false; > if (unlikely(maxlen && len > maxlen)) > return false; > - if (len !=3D 0) { > - p =3D xdr_inline_decode(xdr, len); > - if (unlikely(!p)) > - return false; > - ptr->data =3D (u8 *)p; > - } > + p =3D xdr_inline_decode(xdr, len); > + if (unlikely(!p)) > + return false; > + ptr->data =3D (u8 *)p; > ptr->len =3D len; > return true; > } Reviewed-by: Jeff Layton